“[Hayes] absolutely didn’t know he was heading into a situation that dangerous,” one firefighter told The Post on Sunday. “We’re the Bravest, not the Stupidest.”

A task force of heavily armed NYPD cops and federal agents had gone to arrest Tyree early Friday for a violation of his supervised release. The violent ex-con had a long rap sheet and also was being eyed in two murders, sources said.

Garland Tyree

When the agents got to the home, Tyree told them to beat it. They got a key from his landlord, entered and were met by smoke pouring up from his basement apartment.

The squad called the Fire Department and Hayes’ unit was the first on the scene.

“They didn’t tell us about anyone in the house or what was going on,’’ a second firefighter said. “They allowed us to walk in there without telling us what was going on.”

But law-enforcement sources said Hayes and his men were definitely given a summary of the situation and told that Tyree might be armed. Hayes was warned not to enter the home with Tyree still inside, they said.

A source added that the scene was teeming with heavily-armed law-enforcement agents and that Hayes should have had an idea the situation was volatile.

Regardless, he put duty over his own well being, the source said. It turned out that Tyree had set off a smoke bomb, and there was no fire.

“At the end of the day, his heart was in the right place,” the source said of the Bravest’s Hayes.

FDNY personnel rarely take part in fugitive arrests or warrant executions, so protocols for those situations are murky at best, several sources acknowledged.

Tyree held cops at bay for six hours before being fatally gunned down by members of an ESU team after he finally emerged from the house firing an AK-47 assault rifle.